Windshield Wipers

I have a 1998 Mitsubishi Montero Sport. My windshield wipers will work and stop and than start again. The stop periods being a lot longer than periods when the wipers are actually working. As everyone already knows this makes for very dangerous road conditions. I know nothing about cars, but I know it has to be something internal, since I replaced the wiper blades with no luck. Any insight would be greatly appreciated.

which wiper speed setting does this occur in?